Make toolbar responsive and print canvas only

[code-by-sia]

Summary

• Makes the app shell use 100dvh with overflow containment so the sheet keeps the remaining workspace on small screens.
• Adds mobile toolbar rules for scrollable tabs, compact tab labels, horizontally scrollable ribbon groups, wrapped button rows, and tighter formula-bar controls.
• Adds print media rules that hide the ribbon, formula bar, and status bar so printing outputs only the sheet canvas.
• Rebuilds the GitHub Pages docs bundle.

Validation

• npm test
• npm run typecheck
• npm run build
• Browser check at a narrow viewport confirmed no app-level horizontal overflow and the canvas remains visible below the toolbar.
• Browser CSSOM check confirmed the print media rules are loaded.

Note: npm run build still reports the existing direct eval warning in src/lib/core/formula/Evaluator.ts; it does not block the build.